House-hacking has many benefits that one can utilize, so you should definitely consider it!

We separated and updated the utilities.

I thought about utilizing that property for storage space.

So, I would basically consider it an up/down duplex that does not have separate utilities.

Therefore we look out for their best interest as well as the help, safety and welfare of the public/anyone whom will utilize the space(s).  

Get those CCs paid down, and you'll also potentially earn higher credit limits on those existing cards (a good rule of thumb is to keep your utilization lower than 30% of your limit which, if done consistently, can boost your credit score). 

Does it make sense to include internet with the utilities (that I already pay) to possibly rent my units for more money than similar properties?

If you cannot produce that paperwork because the money is actually in your possession or sitting in your accounts or in a safe, that's when you'll wish you had established that account.

You provide the space and utilities.

I might have need to utilize these funds for other reasons in the next year or 2 as well - if other investment opportunities arise, if we move into a bigger house, if I decide to go the self-employment/small business route.